And here it's directly mentioned in the guidelines of how 'Show HN' should work:
https://news.ycombinator.com/showhn.html
> Please don't ask friends to upvote or comment. That's not ok on HN.
https://news.ycombinator.com/newsfaq.html#ring
> Can I ask people to upvote my submission?
> No. Users should vote for a story because they personally find it intellectually interesting, not because someone has content to promote. We penalize or ban submissions, accounts, and sites that break this rule, so please don't.
> Can I ask people to comment on my submission?
> No, for the same reason. It's also not in your interest: HN readers are sensitive to this and will detect it, flag it, and use unkind words like 'spam'.
https://news.ycombinator.com/showhn.html
> Please don't ask friends to upvote or comment. That's not ok on HN.
https://news.ycombinator.com/newsfaq.html#ring
> Can I ask people to upvote my submission?
> No. Users should vote for a story because they personally find it intellectually interesting, not because someone has content to promote. We penalize or ban submissions, accounts, and sites that break this rule, so please don't.
> Can I ask people to comment on my submission?
> No, for the same reason. It's also not in your interest: HN readers are sensitive to this and will detect it, flag it, and use unkind words like 'spam'.